At present, the most common type of X-ray imaging device is an indirect exchange type. In order to detect an electrical signal that is converted by a scintillator, an active matrix-type TFT array is employed. In the related art, in order to form a thin film transistor element (TFT element) in the TFT array, an a-SI layer is used as a semiconductor layer.
Because of this characteristic of the a-Si layer, the a-Si layer is difficult to use as a semiconductor layer for a drive circuit, such as a gate driver.
Therefore, in the TFT array that includes the a-Si layer, the drive circuit such as the gate driver is formed by being attached from the outside.
In a case where the gate driver is formed in this manner by being attached from the outside, as disclosed in PTL 1 and PTL 2, each scan signal line in the TFT array is partly selected, and thus scanning for setting a High state to be entered (to be active) is possible.
However, in recent years, with a performance improvement resulting from high mobility, a screen-uniformity performance, and the like, a TFT array has been developed that includes an oxide semiconductor layer, for example, an oxide semiconductor layer containing Indium (In), Gallium (Ga), and Zinc (Zn).
In the TFT array that includes the oxide semiconductor layer, gate driver monolithic (hereinafter referred to as CDM), that is, a gate driver, is formed directly on the TFT array, and thus a reduction in the number of components and a reliability improvement are realized.